Surface configuration of a helmet



FIG. 1 is a right, front perspective view of a surface configuration of a helmet showing our new design;

FIG. 2 is a left, front perspective view thereof;

FIG. 3 is a right side view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a front view thereof;

FIG. 6 is a rear view thereof;

FIG. 7 is a right, rear perspective view thereof;

FIG. 8 is a left, rear perspective view thereof; and,

FIG. 9 is a top view thereof.

The dash lines included depict environment and are not part of the claimed design. 

The ornamental design for a surface configuration of a helmet, as shown and described. 